In-wheel motor

Abstract

An in-wheel motor with improved driving force has a simplified cooling structure for the motor and a braking device. The in-wheel motor has a motor that transmits motive power to a wheel, at least a portion of the motor being disposed inside the wheel; a first cooling part and a second cooling part that cool a stator of the motor; and a braking device that applies braking to the wheel. The braking device 25 is formed from a brake disc that rotates with the wheel and a brake caliper that induces braking by imparting friction to the brake disc. The brake caliper operates in the axial direction of the motor to induce braking in the brake disc. A portion of an axial-direction end of the brake caliper is in contact with the stator. The first cooling part and the second cooling part cool the braking device through the stator.

1 . An in-wheel motor comprising a motor at least a part of which is disposed inside a wheel and which transmits power to the wheel, a cooling device that cools a stator of the motor, and a brake device that applies a brake to the wheel,
 wherein the brake device includes a brake disc that rotates together with the wheel, and a brake caliper that applies friction to the brake disc for braking,   the brake caliper operates in an axial direction of the motor to apply a brake to the brake disc,   a part of an axial end portion of the brake caliper is in contact with the stator, and   the cooling device cools the brake device via the stator.   
     
     
         2 . The in-wheel motor according to  claim 1 , wherein
 the stator includes a stator housing that is open on one side in an axial direction and includes a rotor inside, and a stator housing cover that closes an open side of the stator housing,   the stator housing includes a housing annular portion having a cylindrical shape and extending in the axial direction, and a housing flat plate portion extending in a radial direction orthogonal to the axial direction, and   in the brake caliper, an axial end surface of the brake caliper is in contact with the housing flat plate portion.   
     
     
         3 . The in-wheel motor according to  claim 1 , wherein the brake caliper is in contact with the stator via an elastic body having a Young's modulus smaller than Young's moduli of the brake caliper and the stator. 
     
     
         4 . The in-wheel motor according to  claim 1 , wherein a part of the brake caliper is disposed at a position overlapping the stator in a radial direction. 
     
     
         5 . The in-wheel motor according to  claim 4 , wherein
 the stator includes a stator core to which a stator coil is attached, and   the brake caliper is disposed on an inner diameter side of the stator core.   
     
     
         6 . The in-wheel motor according to  claim 1 , wherein the cooling device includes a liquid refrigerant. 
     
     
         7 . The in-wheel motor according to  claim 6 , wherein
 the cooling device includes a first cooling portion through which the liquid refrigerant circulates and a second cooling portion through which the liquid refrigerant does not circulate, and   the brake caliper is in contact with the first cooling portion via the second cooling portion.   
     
     
         8 . The in-wheel motor according to  claim 7 , wherein the first cooling portion and the second cooling portion are formed by partitioning an internal space of the stator with a rotor. 
     
     
         9 . The in-wheel motor according to  claim 1 , wherein the brake caliper is disposed such that a longitudinal direction of the brake caliper is an up-down direction, and
 both end portions of the brake caliper in the up-down direction are fixed to the stator by fixing bolts.   
     
     
         10 . The in-wheel motor according to  claim 1 , wherein the brake caliper is fixed to the stator from the wheel.